removed lazy loading to avoid exceptions in Luna

plugins/org.yakindu.sct.model.sgraph.ui/META-INF/MANIFEST.MF

@@ -13,7 +13,6 @@ Require-Bundle: org.eclipse.ui,
  org.apache.commons.lang,
  org.eclipse.gmf.runtime.emf.core
 Bundle-RequiredExecutionEnvironment: J2SE-1.5
-Bundle-ActivationPolicy: lazy
 Export-Package: org.yakindu.sct.model.sgraph.ui,
  org.yakindu.sct.model.sgraph.ui.refactoring,
  org.yakindu.sct.model.sgraph.ui.validation